Capacitor Discharge: Calculating Rate of Voltage Change and Time

Click For Summary
SUMMARY

The discussion focuses on calculating the time required for a discharging capacitor's voltage to decrease by 90%, given that the instantaneous rate of change of voltage is proportional to the voltage itself, specifically at a rate of 1/100 of the voltage per second. The relevant equation for this scenario is derived from the exponential decay formula, e^-rt. The correct approach involves solving for time t using logarithmic functions, which was initially miscalculated as 4.49 seconds.

PREREQUISITES
  • Understanding of capacitor discharge principles
  • Familiarity with exponential decay equations
  • Knowledge of logarithmic functions
  • Basic algebra skills for solving equations
NEXT STEPS
  • Study the derivation of the exponential decay formula e^-rt
  • Learn how to apply logarithmic functions in real-world scenarios
  • Explore capacitor discharge circuits and their applications
  • Investigate the impact of resistance and capacitance on discharge rates
USEFUL FOR

Students studying electrical engineering, physics enthusiasts, and anyone involved in circuit analysis or capacitor applications will benefit from this discussion.

postman
Messages
2
Reaction score
0

Homework Statement


When a condenser discharges electricity, the instantaneous rate of change of the voltage is proportional to the voltage in the condenser.
Suppose you have a discharging condenser and the instantaneous rate of change of the voltage is 1/100 of the voltage (in volts per second). How many seconds does it take for the voltage to decrease by 90%?


Homework Equations



e^-rt

The Attempt at a Solution

Log 90= e^-t ? = 4.49?
 
Physics news on Phys.org
It's wrong. Try to give a more detailed calculation and explain what it is you do.
 

Similar threads

  • · Replies 4 ·
Replies
4
Views
1K
Replies
20
Views
2K
Replies
6
Views
1K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 10 ·
Replies
10
Views
3K
  • · Replies 4 ·
Replies
4
Views
4K
  • · Replies 9 ·
Replies
9
Views
3K
Replies
8
Views
5K
Replies
8
Views
2K
Replies
1
Views
2K